CN116659668A

CN116659668A - Spectrometer, spectrum reconstruction method and computer equipment

Info

Publication number: CN116659668A
Application number: CN202310652411.8A
Authority: CN
Inventors: 林天华; 严亭; 程祺翔
Original assignee: Xuzhou Guangyin Technology Development Co ltd
Current assignee: Xuzhou Guangyin Technology Development Co ltd
Priority date: 2023-06-02
Filing date: 2023-06-02
Publication date: 2023-08-29

Abstract

The invention relates to the technical field of spectrum detection, and discloses a spectrometer, a spectrum reconstruction method and computer equipment, wherein the spectrometer comprises the following components: a light source; at least one broad spectrum response filter having an input and an output, the input of which receives the light source; the broad spectrum response filter responds to the spectrum of the light source, and outputs different modulation spectrums at the output end of the broad spectrum response filter according to a preset response rule so as to irradiate a sample to be detected; at least one photoelectric detector for collecting scattered or transmitted light intensity information of the sample to be detected after being irradiated by different modulation spectrums; the spectrometer can reduce the loss of the light source in the link transmission, thereby reducing the power consumption of the light source, improving the signal-to-noise ratio of the signal received by the detector and improving the endurance of the equipment.

Description

Spectrometer, spectrum reconstruction method and computer equipment

Technical Field

The invention relates to the technical field of spectrum detection, in particular to a spectrometer, a spectrum reconstruction method and computer equipment.

Background

The spectral characteristics of a substance contain a large amount of information, and can be used for detecting the composition of the substance physically and chemically, and can be used for detecting pathological change information of an organism biologically and the like.

Conventional methods of spectral feature detection are typically implemented by swept lasers or spectrometers.

The working principle of the detection method of the sweep laser is that the laser outputs single wavelength, scattering or absorption information of the single wavelength is obtained by irradiating a sample to be detected and collecting scattered or transmitted light, and then the characteristic information of the whole spectrum is obtained by scanning the sweep laser wavelength by wavelength through the sweep function of the sweep laser. This method requires wavelength-by-wavelength scanning, which increases the working time considerably when the number of required wavelength points is large, which increases the time costs on the one hand and is not suitable for certain rapidly changing samples on the other hand. The price of the sweep frequency laser is also relatively expensive, the volume and the mass are relatively large, and if the wavelength range of the required spectrum information is relatively large, the single sweep frequency laser can not meet the application requirements, and the cost, the volume and the mass can be further increased.

The working principle of the detection method of the spectrometer is that a wide-spectrum light source is used for irradiating a sample, scattered or transmitted light is collected and enters the spectrometer, and the intensity information of light with different wavelengths is obtained through the spectrometer, so that the scattering and absorption characteristics of the sample are calculated. A spectrometer using such a configuration may suffer from certain losses in collecting scattered or transmitted light into the spectrometer. For the spectrometer, the wide-spectrum light source is mainly independently powered, and even if a great loss exists in optical link transmission, the power of the light source can be increased to compensate the loss, so that the detection is not influenced.

Although some miniaturized, portable or wearable devices may be provided with a calculation reconstruction spectrometer to reduce the volume, the same problems as above still exist in some cases, and the problems are limited by the volume and the battery capacity of the device, so that the reliable detection result is ensured, the power consumption of the light source is reduced, and the problem that the continuous voyage of the device needs to be solved by those skilled in the art is solved.

Disclosure of Invention

The present invention aims to solve one of the technical problems in the related art to a certain extent. Therefore, the invention provides the spectrometer, the spectrum reconstruction method and the computer equipment, which can reduce the loss of the light source in the link transmission, thereby reducing the power consumption of the light source and improving the endurance of the equipment.

In order to achieve the above object, the present invention adopts the following technical scheme in a first aspect:

a computationally reconfigurable spectrometer, comprising:

a light source;

at least one broad spectrum response filter having an input and an output, the input of which receives the light source; the broad spectrum response filter responds to the spectrum of the light source, and outputs different modulation spectrums at the output end of the broad spectrum response filter according to a preset response rule so as to irradiate a sample to be detected; the method comprises the steps of,

and the at least one photoelectric detector is used for collecting scattered or transmitted light intensity information of the sample to be detected after being irradiated by different modulation spectrums.

In the prior art, after a light source passes through a sample to be detected, scattered light enters a filter through a slit or an optical fiber, which cannot be oriented in a concentrated manner, due to the disorder and the increase of the optical expansion, and link loss exists. Compared with the prior art, the light source is ordered and has small optical expansion when in use, and can enter a wide-spectrum response filter through the optical waveguide directly or after being modulated (through some optical elements), the wide-spectrum response filter outputs different modulation spectrums according to a prefabricated response rule to irradiate a sample to be detected, and the light beam can be scattered when passing through the sample to be detected, and the disorder and the optical expansion are increased, but can still be received by the photoelectric detector. Each photodetector can measure and convert optical signals of different wavelengths into electrical signals. By arranging a plurality of photodetectors to perform a two-dimensional array or a one-dimensional array (e.g., circular or parabolic), the coverage area and range can be increased, so that scattered light passing through a sample (or a sample) to be measured at different angles can be detected as much as possible. Therefore, the scheme can reduce the loss of light on the transmission link, so that more light can enter the wide-spectrum response filter and can be fully received by the photoelectric detector after being scattered by a sample to be detected, the utilization rate of light in the whole process is improved, and the endurance of equipment is also improved due to the reduction of the energy consumption of the light source.

In the invention, it is further preferable that an optical window for placing a sample to be measured is arranged between the output end of the broad spectrum response filter and the photoelectric detector; the output end of the broad spectrum response filter faces the optical window at an irradiation angle to generate scattered light on the surface of the sample to be detected; the photoelectric detector is arranged around the irradiation center of the output end of the wide spectrum response filter on the optical window so as to receive scattered light intensity information; the angle between the direction from the photodetector to the irradiation center and the optical window is a receiving angle, and the receiving angle is (0 degree, 90 degrees).

It is further preferred in the present invention that the illumination angle is 90 ° and the photodetector is wrapped around the perimeter of the broad spectrum response filter.

In the present invention, it is further preferable that a space for placing a sample to be measured is provided between the output end of the broad spectrum response filter and the photodetector, and the output end of the broad spectrum response filter generates transmitted light through the sample to be measured in the space.

In a further preferred embodiment of the present invention, the broad spectrum response filter is a tunable filter, and only one broad spectrum response filter is provided; the tunable filter, in use, establishes the spectral response matrix by tuning multiple times to form multiple optical channels in time sequence to output different modulated spectra.

In the present invention, it is further preferable that the wide-spectrum response filter is a filter having an optical waveguide structure.

In the present invention, it is further preferable that the filter of the optical waveguide structure is a Fabry-Perot filter.

In the present invention, it is further preferable that the filter of the optical waveguide structure is a Bragg grating filter.

In the present invention, it is further preferable that the filter of the optical waveguide structure is a Mach-Zehnder interference filter.

It is further preferred that the present invention is configured on a miniaturized, portable or wearable device when in use.

In the present invention, it is further preferable that the filter of the optical waveguide structure is a filter of a single-mode waveguide structure.

In the present invention, it is further preferable that the filter of the optical waveguide structure is a filter of a multimode waveguide structure.

The waveguide filter has lower optical expansion, higher order requirement on photons coupled into the waveguide, and more obvious improvement on coupling efficiency. Measured as etendue, then their relationship is: the single mode waveguide is less than the multimode waveguide is less than the slit.

In a further preferred embodiment of the present invention, the photodetectors are surface photodetectors, and only one of the photodetectors is provided. A face photodetector is a special type of photodetector, also known as a face array photodetector. It is composed of a plurality of photodetector units, which are arranged on a two-dimensional plane to form an array structure. Each cell can independently measure an optical signal and convert it into an electrical signal.

The surface photoelectric detector has the advantages of high spatial resolution, real-time imaging, convenient integration, high sensitivity and the like compared with a photoelectric detector array.

Since the face photodetectors are two-dimensionally arrayed, a higher spatial resolution can be provided; the surface photoelectric detector can acquire two-dimensional image data in a real-time manner, and can acquire the whole image simultaneously in a short time; the surface photoelectric detector is usually integrated with a plurality of photoelectric detector units on a chip, and the integrated structure makes the surface photoelectric detector more compact and convenient to use, and can be easily integrated with other electronic equipment and systems; the face photodetector improves sensitivity by measuring multiple optical signals simultaneously. The optical signals can enter the photoelectric detector units from different angles or positions, so that the light receiving capacity is enhanced, and the surface photoelectric detectors can be arranged on the hemispherical surface taking the irradiation center of the sample to be detected as the sphere center to receive scattered light from different angles.

It should be noted that in practice, a face photodetector may be regarded as a special case of a photodetector array, i.e. photodetectors arranged in a two-dimensional plane.

In the present invention, the spectral width of the light source is more preferably 200nm, 500nm or 1000 nm.

It is further preferred in the present invention that the light sources are all SLED light sources, and that all SLED light sources cover the spectrum width when operated simultaneously.

The invention further preferably provides that the output end of the broad spectrum response filter is provided with a first lens so as to increase the light intensity of the modulation spectrum on the sample to be detected; alternatively, a second lens is provided before the photodetector to enable the photodetector to collect a greater spatial range of light.

In addition, the invention also provides a spectrum calculation reconstruction method in the second aspect, which comprises the steps of constructing a spectrum response matrix, establishing an underdetermined equation set, solving the underdetermined equation set and spectrum reconstruction; wherein the spectral response matrix and the underdetermined equation are established by the spectrometer described in the first aspect, respectively.

The spectrum calculation reconstruction method provided by the invention is similar to the beneficial effect reasoning process of the spectrometer, and is not repeated here.

The present invention also provides in a third aspect a computer device comprising a memory storing a computer program and a processor implementing the spectral calculation reconstruction method according to the second aspect when the processor executes the computer program.

These features and advantages of the present invention will be disclosed in more detail in the following detailed description and the accompanying drawings. The best mode or means of the present invention will be described in detail with reference to the accompanying drawings, but is not limited to the technical scheme of the present invention. In addition, these features, elements, and components are shown in plural in each of the following and drawings, and are labeled with different symbols or numerals for convenience of description, but each denote a component of the same or similar construction or function.

Drawings

The invention is further described below with reference to the accompanying drawings:

fig. 1 is a schematic diagram of a spectrometer according to the present invention.

Fig. 2 is a schematic diagram of a spectrometer, in an exemplary embodiment, illustrating a multiple light source multiple filter configuration.

Fig. 3 is a schematic diagram of a spectrometer, in an exemplary embodiment, showing an adjustable broad filter and an area photodetector.

Fig. 4 is a schematic structural diagram of the spectrometer in an exemplary embodiment, which shows a spectrometer applied to a smart watch or a bracelet.

Fig. 5 is a schematic structural diagram of the spectrometer in an exemplary embodiment, showing the manner of switching the filter to realize time-sharing multiplexing of the broad spectrum light source and the photodetector.

Detailed Description

Embodiments of the present invention are described in detail below, examples of which are illustrated in the accompanying drawings, wherein like or similar reference numerals refer to like or similar elements or elements having like or similar functions throughout. The examples in the embodiments are intended to illustrate the present invention and are not to be construed as limiting the present invention.

Reference in the specification to "one embodiment" or "an example" means that a particular feature, structure, or characteristic described in connection with the embodiment itself can be included in at least one embodiment of the present patent disclosure. The appearances of the phrase "in one embodiment" in various places in the specification are not necessarily all referring to the same embodiment.

The inventor finds that, because the principle of the spectrometer determines that a light beam must enter the spectrometer from a small size to effectively resolve spectrum information, the input end of the conventional spectrometer is usually made into a slit or an optical fiber, the light beam after passing through a sample is scattered, the disorder and the optical expansion thereof are increased, and a great amount of energy is lost when the light beam is coupled into the slit or the optical fiber, which represents that the detector array of the receiving end must have very high sensitivity and responsivity. This places on the one hand extremely high demands on the detector array, which increases costs, and on the other hand very poor resolution for weak transmitted or scattered light due to link losses.

In a general spectrometer scheme, a light source is required to irradiate a sample to be measured, scattered light is generated, the scattered light can not enter a filter through a slit or an optical fiber in a centralized orientation due to disorder and increase in optical expansion, link loss exists, the loss is usually between 10% and 99.9%, the smaller the slit or the smaller the clear aperture of the optical fiber, the higher the resolution and the increase in loss. For photonic chip spectrometers applications, especially computationally reconfigurable spectrometers, it is desirable to couple spatially diffracted light into single mode optical fibers or waveguides, which can have losses above 99%. If the above-mentioned computational reconstruction spectrometer is integrated in a miniaturized, portable or wearable device, the endurance is also a serious challenge, which seriously hinders the application of the device in the miniaturized, portable or wearable device.

As shown in fig. 1, the present embodiment proposes a computationally reconfigurable spectrometer, which includes a light source, at least one broad-spectrum response filter, at least one photodetector, and a working area for placing a sample to be measured.

The working area is arranged at the output end of the broad spectrum response filter, so to speak, before the broad spectrum response filter is arranged on the sample to be tested, the light generated by the broad spectrum light source directly or after being modulated (through some optical elements), enters the broad spectrum response filter through the optical waveguide, irradiates the sample to be tested to scatter, and is finally received by the photoelectric detector.

In the process, the sequence of light in the original link transmission process is changed, the light source generates light with relatively orderly and small optical expansion, the light almost does not damage the light enters the wide-spectrum response filter through the optical waveguide, and then a plurality of photoelectric detectors are arranged to perform two-dimensional array or one-dimensional array (such as ring or parabola), so that the coverage area or range can be increased, and scattered light passing through a sample to be detected can be detected as much as possible.

Therefore, the loss of light on a transmission link can be reduced, more light can enter the wide-spectrum response filter and can be fully received by the photoelectric detector after being scattered by a sample to be detected, the utilization rate of light in the whole process is improved, and the cruising time is also improved due to the reduction of the energy consumption of a light source.

In some embodiments, if the wide spectral response filter used is a spatially coupled filter, the loss is negligible. In other embodiments, if the broad-spectrum response filter employs an integrated photonic chip, its coupling loss is < 30%. The huge difference in loss brings about different tolerance to noise, for example, the noise introduced by a photoelectric detector and a circuit is 20dB on a filter front-end structure spectrometer, and the noise introduced by a general spectrometer can be 2dB (1:70 signal strength), which is a great degradation of a spectrometer index. The traditional solution is to boost the light source, the PD (photodetector), or the circuit, and the light source optical power is increased by 70 times or the PD and circuit noise are reduced by 70 times to achieve the same effect. The invention can solve the problems just by changing the position of the filter.

Therefore, the scheme of the invention greatly improves the performance of the spectrometer, and can have beneficial effects in any field where the spectrometer can be applied, especially in the aspect of weak spectrum detection. Specific fields may include spectroscopic analysis in the field of communications, harmful gas spectroscopic monitoring, water quality spectroscopic monitoring, spectroscopic monitoring of various substances of the human body (blood oxygen, blood lactic acid, blood sugar, blood fat, etc.), soil spectroscopic monitoring, etc.

Specific embodiments of the light source, the broad-spectrum response filter, and the photodetector are described in detail below.

In particular embodiments, the light source employs a broad spectrum light source, which may be designed to have a spectral width above 60nm, above 200nm, or above 500nm, or above 1000 nm. The wide-spectrum light source comprises a plurality of light sources which are positioned in different wave band ranges and can work independently, and a plurality of light sources can be selectively combined to work according to the requirements of practical application scenes. In some embodiments, the light source may also be a single light source with a narrower spectrum width, and the specific application may also be selected according to the actual situation.

As shown in fig. 2, the broad spectrum light sources are each preferably a plurality of SLED light sources, all of which, when operated simultaneously, cover the range of the spectral width. SLED is an abbreviation for Superluminescent Light Emitting Diode (ultra-bright light emitting diode), which is a special type of light emitting diode. SLED has a wider spectral bandwidth and higher brightness than conventional Light Emitting Diodes (LEDs).

SLEDs operate on similar principles to LEDs, but differ in structure. It is typically composed of a series of layers of semiconductor material, including a light emitting layer and a light reflecting layer. This structure generates light by means of stimulated radiation when an excitation current is passed. Because of the optical enhancement mechanism present in SLED, it can provide a wider spectral bandwidth and higher output power than conventional LEDs.

The wavelength range of SLED depends on its specific design and fabrication. Common SLED wavelength ranges include visible light, near infrared light, and mid infrared light. The wavelength of SLED is typically between 400 nm and 700 nm in the visible range. Whereas in the near infrared range the wavelength can extend from 800 nm to thousands of nm. For the mid-infrared range, wavelengths may extend from a few microns to tens of microns.

It should be noted that the specific SLED wavelength range depends on factors such as material selection, device structure, and fabrication process. Different SLED products may have different wavelength ranges and output power characteristics, so that the invention needs to be properly selected according to the application requirements when selecting and using.

In some embodiments, the spectrometer is configured on a miniaturized, portable, or wearable device, the broad spectrum response filter having an input and an output, the input of which is connected to the broad spectrum light source by an optical waveguide. The broad spectrum response filter is configured to receive and respond to the spectrum of the broad spectrum light source through the optical waveguide and output different modulation spectrums at an output end thereof according to a preset response rule.

In order to reduce the number of broad spectrum response filters and the space occupied in the chip, as shown in fig. 3, in some embodiments, the broad spectrum response filters are tunable filters, which may be provided with only one. The tunable filter, in use, establishes the spectral response matrix by tuning multiple times to form multiple optical channels in time sequence to output different modulated spectra.

The tunable filter may be a liquid crystal filter (Liquid Crystal Filter) that uses the electro-optic effect of the liquid crystal material to adjust the spectral range through the filter. By controlling the applied voltage, adjustment of the wavelength range can be achieved. The liquid crystal filter can be adjusted in a wider wavelength range and has higher optical transmittance and modulation speed.

The tunable filter may also be an Acousto-optic tunable filter (AOTF) (Acousto-Optic Tunable Filter), which uses the Acousto-optic effect to adjust the light transmission characteristics. It is used to achieve wavelength selection by applying acoustic vibrations to change the refractive index of the light. The acousto-optic tunable filter can be tuned rapidly and accurately over a wide range of wavelengths.

The tunable filter may also be a thermally tunable filter, which is a device that uses thermal effects to alter the optical characteristics of the filter. It typically uses a heat source and a temperature control system to change the operating temperature of the filter to adjust its transmission or reflection characteristics.

In some exemplary embodiments, the broad spectrum response filter is a filter of an optical waveguide structure. The filter of the optical waveguide structure is a Fabry-Perot filter. The Fabry-Perot filter uses interference effects between optical waveguides to achieve a filtering function. It consists of an air cavity between two mirrors, at least one of which is translucent. By adjusting the cavity length or changing the transmittance of the mirror, light of a specific wavelength can be selectively transmitted or reflected.

As one of the above alternative embodiments, the filter of the optical waveguide structure may also be a Bragg grating filter. Bragg grating filters utilize periodic refractive index modulation structures to selectively reflect or transmit light of a particular wavelength through the Bragg reflection effect. Such filters are typically composed of periodic refractive index modulation regions on an optical waveguide, and by varying the period and depth of the refractive index modulation regions, different filter characteristics can be achieved.

As one of the above-described alternative embodiments, the filter of the optical waveguide structure may also be a Mach-Zehnder interference filter. The Mach-Zehnder interference filter utilizes interference effects in the optical waveguide to realize a filtering function. The optical fiber coupler consists of a beam splitter, two optical waveguide transmission paths and a re-coupler. By adjusting the path length or phase difference, light of a particular wavelength can be selectively transmitted or reflected.

It should be noted that, here, the broad spectrum response filter means that the spectral width of the response spectrum is wide, and the broad spectrum response filter includes a plurality of filters arranged spatially or one filter adjustable in time sequence. If the spectral width of the spectrum is X, the corresponding spectral width of the n spatially arranged broad spectrum response filters is X ₁ -X _n X is then ₁ ∪X ₂ ∪…∪X _n Not less than X; if the spectrum width of the spectrum is X, an adjustable filter can respectively modulate the corresponding spectrum width to be X in time sequence ₁ -X _n N filters of (2) also satisfy X ₁ ∪X ₂ ∪…∪X _n ≥X。

The photoelectric detector is used for collecting scattered or transmitted light intensity information of the sample to be detected after being irradiated by different modulation spectrums. In order to collect scattered light at different angles, a two-dimensional array or a one-dimensional array (e.g., circular or parabolic) of photodetectors is provided to increase the coverage area (range) so that as much scattered light as possible can be detected through the sample (or specimen) to be measured. In some embodiments, the photodetectors are face photodetectors, referring to fig. 3 and 4, which can be regarded as a special case of a photodetector array, i.e., photodetectors arranged in a two-dimensional plane, so that the photodetectors can be provided with only one.

It should be noted that, as shown in fig. 5, in the case of using only one plane photodetector, it may correspond to multiple channels or multiple broad spectrum filters, and the broad spectrum light source and the photodetector are time-division multiplexed by switching the broad spectrum filters, so that not only the signal intensity can be improved, but also the spectrum distribution of the light source and the response distribution of the photodetector can be ensured to be completely consistent, and the signal-to-noise ratio is further increased, so as to obtain a better spectrum recovery result.

It should be noted that there are two embodiments of the broad-spectrum response filter, the working area, and the spatial arrangement of the photodetectors. Referring to fig. 1-3, one is to locate the working area between the output end of the broad spectrum response filter and the photodetector, and the spectrum coming out of the broad spectrum response filter can directly pass through the sample to be measured and generate transmission light to be detected by the photodetector. In practice, a channel space may be provided between the output of the broad-spectrum response filter and the photodetector to form the working area for the sample to be measured to enter. This is mainly used for detecting transparent or semitransparent samples, such as gases, liquids.

Referring to fig. 4, another approach is to provide an optical window between the output of the broad-spectrum response filter and the photodetector. In specific implementation, transparent glass can be used as an optical window, and the surface of the transparent glass is a working area for placing a sample to be measured. The spectrum analyzer is configured on the intelligent watch for detecting the composition of a certain substance in the subcutaneous blood vessel of the human body, and only the purpose-made sample to be a non-uniform medium or particle can be utilized, so that when the light encounters a microstructure, particles or other scattering centers in the substance, the light deviates or changes the propagation direction in all directions. These scattered light may be collected by a photodetector.

It should be noted that, in some exemplary embodiments, a first lens may be disposed between the output end of the broad spectrum response filter and the sample to be measured to perform condensation or collimation, so that the light irradiated to the sample to be measured is stronger, and then the area is more concentrated during scattering, which is conducive to obtaining a scattering spectrum with better uniformity. In addition, a second lens can be arranged between the sample to be detected and the photoelectric detector to collect light in a larger space range to the photoelectric detector, so that the signal-to-noise ratio is increased.

In addition, the light source irradiates human skin in the using process of the spectrometer, and a small amount of loss is caused when the light source passes through the filter due to the fact that a threshold value exists in the adaptability of the human skin, so that the spectrometer with the front filter can reduce the light source intensity, and the loss of the filter can be fully utilized to reduce the stimulation of the light source to the human skin. The existing spectrometer which adopts a light source to pass through a sample to be detected firstly can certainly increase the irradiation intensity to the skin of a human body due to the need of a high-power-consumption light source, and the irradiation with the too high intensity can cause discomfort to people sensitive to the skin and even can generate burning feeling.

In some exemplary embodiments, a working surface for attaching a sample to be tested is provided on one side of the transparent glass, and the working area is located on the side where the working surface is located. The output end of the broad spectrum response filter faces the working surface at an illumination angle, and the photoelectric detector is arranged around the illumination center of the output end of the broad spectrum response filter on the working surface.

Wherein the illumination angle is the angle between the working face and the direction from the output end of the broad spectrum response filter to the illumination center. The included angle between the direction from the photoelectric detector to the irradiation center and the working surface is a receiving angle, and the receiving angle is (0 degree, 90 degrees).

More specifically, the illumination angle is 90 °, and the photodetector surrounds the perimeter of the broad spectrum response filter. The photoelectric detector is a plane photoelectric detector, and the plane photoelectric detector is an annular plane and is arranged on a hemispherical surface taking the irradiation center of a sample to be detected as the center of a sphere.

As an alternative embodiment, the illumination angle is 45 °, and the photodetector is semi-looped around the perimeter of one side of the broad spectrum response filter. As shown in fig. 4, only a photodetector in which the irradiation angle and the reception angle are on the same plane is illustrated, and the reception angle is illustrated as 45 ° in the drawing.

The embodiment also provides a spectrum calculation reconstruction method, which comprises the steps of constructing a spectrum response matrix, establishing an underdetermined equation set, solving the underdetermined equation set and spectrum reconstruction. Wherein the spectral response matrix and the under-determined equation are established by the above-described spectrometer, respectively.

Constructing a spectral response matrix: first, a set of samples of known input spectra need to be obtained by experiment or simulation and the corresponding output signals measured. These input spectra may be a series of samples of known wavelength and light intensity. The input spectrum is subjected to simulation or experimental measurement by an optical system of the computational reconstruction spectrometer, so that a corresponding output signal can be obtained. And using the input spectrums and the corresponding output signals as data to construct a spectrum response matrix.

Establishing a system of underdetermined equations: based on the principle of the calculation reconstruction spectrometer and the spectral response matrix, a system of underdetermined equations can be established. The unknown quantity of the equation set is the spectrum of the sample to be measured, and the equation of the equation set is derived from the relation between the input spectrum and the output signal, and is mapped through the spectrum response matrix.

Solving a system of underdetermined equations: since the system of equations is underdetermined, i.e. the unknown (spectrum of the sample to be measured) is more than the number of equations, it cannot be solved directly. In this case, a suitable mathematical method is required to solve the system of equations. Common solution methods include Least Squares (Least Squares), regularization (Regularization), and the like.

And (3) spectrum reconstruction: and obtaining a spectrum estimation result of the sample to be measured by solving the underdetermined equation set. This estimation may represent the spectral information of the sample under test under the computational reconstruction spectrometer.

The working principle thereof is described in detail below in connection with specific embodiments. As shown in fig. 1, the spectrometer comprises a broad spectrum light source (non-laser light source, 3dB bandwidth > 1 nm), a plurality of broad spectrum filters, a sample to be measured and a plurality of photodetectors. The broad spectrum light source passes through different broad spectrum filters, the spectrum is modulated, different modulation spectrums irradiate the sample and then are absorbed or scattered by the sample, and a photoelectric detector, namely a PD is used for collecting light intensity signals.

Mathematically, the spectral range to be detected is decomposed into multiple segments, corresponding to (λ1, λ2, λ3,..λn), respectively.

Vector for intensity distribution of broad spectrum light source in spectrum (A _λ1 ,A _λ2 ,A _λ3 ,...A _λn ) A representation;

vector for filter curve of wide spectrum filter (f _λ1 ,f _λ2 ,f _λ3 ,...f _λn ) To represent;

spectral characteristics of the sample to be measured are measured by vector (X _λ1 ,X _λ2 ,X _λ3 ,...X _λn ) To represent;

response curve passing vector of photodetector (D _λ1 ,D _λ2 ,D _λ3 ,...D _λn ) And (3) representing.

The light intensity of the light emitted from the broad spectrum light source is modulated into (A) after passing through the broad spectrum filter _λ1 f _λ1 ,A _λ2 f _λ2 ,A _λ3 f _λ3 ,...A _λ _n f _λn )，

After the spectral curve to be measured passes through the sample to be measured, the spectral information is changed again, and the method (A _λ1 f _λ1 X _λ1 ,A _λ2 f _λ2 X _λ2 ,A _λ3 f _λ ₃ X _λ3 ,...A _λn f _λn X _λn ) A representation;

the information is collected by the photodetector and reflected as an electrical signal with the intensity ofWherein A is _λn D _λn f _λn Determined by the device chosen by the system, as a known term, for descriptive simplicity, the parameter is subsequently determined by S _n Expression, X _λn The spectral characteristics of the property to be measured are unknown.

If m groups of wide spectrum filters are used for respectively collecting the detection light intensity of each group of wide spectrum filters, an equation set can be obtained and expressed by the following matrix

Wherein the method comprises the steps ofSystem remover for system-dependent parametersThe characteristics of the component are determined mainly by the design of each filter, +.>For the spectral properties to be measured +.>Is the value detected by the detector.

Research shows that when m<<n, by constructing a matrixSo that they have good uncorrelation, can solve +.>Is a numerical value of (2). It is clear that m represents the number of filters or channels required and n represents the resolution of the acquired spectral characteristics, which means that by designing the filter characteristics of each filter only a very small number of filters or channels is required to acquire spectral characteristics of very high resolution.

Meanwhile, the embodiment also provides a computer device, which comprises a memory and a processor, wherein the memory stores a computer program, and the processor realizes the steps of the spectrum calculation reconstruction method when executing the computer program. The computer device may here be a wearable device such as a smart watch, a smart bracelet, a smart helmet, etc.

Those skilled in the art will appreciate that implementing all or part of the processes in the methods of the embodiments described above may be accomplished by computer programs to instruct related hardware. Accordingly, the computer program may be stored in a non-volatile computer readable storage medium, which when executed, performs the method of any of the above embodiments.

The above is only a specific embodiment of the present invention, but the scope of the present invention is not limited thereto, and it should be understood by those skilled in the art that the present invention includes but is not limited to the accompanying drawings and the description of the above specific embodiment. Any modifications which do not depart from the functional and structural principles of the present invention are intended to be included within the scope of the appended claims.

Claims

1. A computationally reconfigurable spectrometer, comprising:

a light source;

2. The spectrometer according to claim 1, wherein an optical window for placing a sample to be measured is provided between the output of the broad-spectrum response filter and the photodetector; the output end of the broad spectrum response filter faces the optical window at an irradiation angle to generate scattered light on the surface of the sample to be detected; the photoelectric detector is arranged around the irradiation center of the output end of the wide spectrum response filter on the optical window so as to receive scattered light intensity information; the angle between the direction from the photodetector to the irradiation center and the optical window is a receiving angle, and the receiving angle is (0 degree, 90 degrees).

3. The spectrometer of claim 2, wherein the illumination angle is 90 ° and the photodetector is wrapped around the perimeter of the broad spectrum response filter.

4. The spectrometer of claim 1, wherein a space for placing a sample to be measured is provided between the output of the broad-spectrum response filter and the photodetector, and the output of the broad-spectrum response filter generates transmitted light through the sample to be measured in the space.

5. The spectrometer of claim 1, wherein the broad spectrum response filter is a tunable filter, the broad spectrum response filter being provided with only one; the tunable filter, in use, establishes the spectral response matrix by tuning multiple times to form multiple optical channels in time sequence to output different modulated spectra.

6. The spectrometer of claim 1, wherein the broad spectrum response filter is a filter of an optical waveguide structure.

7. The spectrometer of claim 1, wherein the photodetector is a face photodetector.

8. The spectrometer of claim 1, which, in use, is configured on a miniaturized, portable or wearable device.

9. The spectrometer of claim 1, wherein the light sources are SLED light sources.

10. The spectrometer of claim 1, wherein a first lens is provided at the output of the broad spectrum response filter to increase the intensity of the modulated spectrum on the sample to be measured; alternatively, a second lens is provided before the photodetector to enable the photodetector to collect a greater spatial range of light.

11. A spectrum calculation reconstruction method comprises the steps of constructing a spectrum response matrix, establishing an underdetermined equation set, solving the underdetermined equation set and spectrum reconstruction; characterized in that the spectral response matrix and the underdetermined equation are established by means of a spectrometer according to any of claims 1-10, respectively.

12. A computer device comprising a memory and a processor, characterized in that the memory stores a computer program, which processor, when executing the computer program, implements the spectral calculation reconstruction method as claimed in claim 11.